S-Web Reports
) I will also make a few personal comments.
Here goes:
My first report, about 6 month after joining Siemens.
We certainly had a rather good infrastructure for doing analytics. As far as the report is concerned: Forget the first authors. Hr supervised. Karl Geim, a physicist, was doing all the electrical measurements, Bernhard Freiensrtein did the dipping experiments. The rest, especially the “theoretical” stuff about crystallization and the defect etching part was my contribution. But between the lines you read that I became scepticaal about the proposed technique.
After half a year or so at Siemens, it was clear to me that the S-Web project couldn’t work as intended. I felt I must inform my superiors and wrote my first single-author report, outlining right away that I would be provocative. In essence I put down what I had figured out so far about liquid Si inside the meshes of some net, and introduced the basic concept of dies (“Ziehdüsen”) for achieving coverage of the net. Note that the focus of the experiential work then and for some time to come was to produce decent coverage of the net at all. Doing that at high speed and with small expense was a topic dutifully mentioned in reports but seen as near impossible in reality.
Note that I’m now the project leader of the S-Web technique. Not something I aspired to be.
There are also some numbers concerning costs. Note: "KP"=kontierendes Personal=Angestellte (meaning real people, getting a salary in contrast to workers, appearing as costs)
By now it was abundantly clear that the original plan to produce S-Webs (completely summarized in Fig. 2 (=Abb. 2) could not work. Dr. Falckenberg was charged with building the S-Web machines and got a bit desperate. He wrote almost all of this report and drew most figures, probably to show that he (plus me) were nevertheless of good cheer. The large number of possible ways to do the job (including rather loony ones) discussed in this report shows exactly the opposite. We had no idea of what would be the best approach.
Some success with the "Zeihdüse" (my input). But we had to try the old (loony) ideas first.
My major input for the S-Web, put down in some detail for internal use. As far as I was concerned, this was just pointing out the “obvious” as far as the “mechanics” of solid-liquid interfaces was concerned. For my colleagues and bosses, this was “theory”. It took me some time to learn all that but I didn’t consider it “high” physics. I was far more interested to unravel the secrets of the solid-liquid interface with some current running through it, i.e. the electrochemistry of semiconductors. Figuring out why voltage / current oscillations occurred under certain conditions would have constitute “high” physics as far as I was concerned.
As those reports go, everything is just fine. Interesting are the costs expected (in DM, of course) for just this part of the total project. Siemens did throw serious money on the solar energy issue, after all.
It’s done” We gave a decent piece of S-Web silicon; witness Abb. 8b. It’s all thanks to Dr. Falckenberg and his people who designed or optimized the complex equipment needed to pull the fiber net through liquid silicon. That involved a lot of patient optimizing and some frustration tolerance. I could not have done this kind of work as well as he did. Mrs. Lore Bernewitz, by the way, was the extremely competent and experienced technician who did all the “metallography” work. She already worked for Bernd Kolbesen during our swirl research, was moved to my group in the early 80ties and eventually made it back to Kolbesen’s new group while I moved on to greener pastures. Of course, we were still far off the goal of using nets 1 m wide and pulling with 100 cm/min. And while nobody talked about it, we all knew that it was extremely unlikely that one could ever meet solar cell cost targets with the S-Web
The big report to the funding agency. Written long after I left the group (2nd half of 1983). S-Web Si of decent quality has been produced, based on (my) theory (read it).
Otherwise not much seems to gave happened.
Could not resist. This input to some “Absclussbericht” was written by me some time in 1983, demonstrates three things:
- I liked to needle my superiors. Look at the Motto on the upper right hand corner: “Uns ist in alten Mären (loc cit 13=reference to the original proposal) wunders viel geseit” (To us in olden story / are wonders many told ) is the beginning of the Nibelungen Saga, the major mythological old saga in Germany. I quote it as “Nie gelungen Saga”, a word play translating as “never achieved Saga”.
- Writing a report in those ancient times meant hand-writing the thing, then finding a secretary who would type it. Said sectary also need to format it just right so pictures (provided as photographic prints) and drawings (provided by a specialist who could make nice drawings out of the sketches you provided) could be inserted art the right place. The you handed it to your superiors, who, of course, wanted changes, so you had to find a secretary...
- In the final version the motto and all critical remarks somehow didn’t appear any more. Not surprising, though.
After some internal back-and-forth, outphasing and inphasing, Siemens eventually terminated the S-Web and related projects
With frame
5. Siemens Research Munich; 5.1 Solar Cell Research; 5,1,1 1 Introduction